A conventional switch mechanism for a stapler generally includes a window in the trigger and the window is located corresponding to the safety rod. An eccentric rod is pivotably connected to the trigger and a top plate is connected to the eccentric rod, the top plate has stepped surface which is located outside of the window. The relative position between the stepped surface of the top plate and the safety rod can be adjusted by operation of the eccentric rod. However, when the eccentric rod is located beneath a hole in the trigger, the eccentric rod might be moved upward and/or shakes due to vibration when operating the stapler. There lacks a suitable locking means to set the position of the eccentric rod so that the switch mechanism is not reliable.
In order to position the eccentric rod, a spring with a significant force is needed, but the spring increases the difficulty to the user to operate the eccentric rod.
The present invention intends to provide a reliable switch mechanism which can switch the single-shoot mode and the continuous-shoot mode of the stapler.